Fig. 4. Effect of soil moisture content on the difference between the expected cation and anion concentrations and the measured cation and anion concentrations in the soil solution of an Oxisol with NaCl added at 1 g kg^–1 [O-S(1)] and an Oxisol with NaCl added at 2 g kg^–1 [O-S(2)]. The expected cation and anion concentrations were calculated from the Na and Cl added, the moisture content of the soil, and the soil solution cation and anion concentrations of the Oxisol with no NaCl added.